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Re: (IAAC) brodband filter



You willnot find such a solution as most objects such as stars and the
collections thereof emit of a broad range that just happens to be where our
eyes peak at. Thi smeans that most man made sources are in that zone and a
broad band filter will do little more than decrease the light and usually
colour it a strong blue. It  make mkae dust lanes show up better in some
galaxies but in general a narrow band or line feature will help enormously
with nebulae especially from a light polluted environment. As for red
filters most of the red emissions from Hydrogen appear beyond the
sensitivity of your eye so a red filter will not help much visually


At 09:50 15/07/99 EEST, you wrote:
>Actually NGC 55 is extremely difficult from 40N lattitude. NGC 253 and much 
>fainter NGC 247 are in better dec.
>
>I have some questions about filters. I will be glad if you answer me.
>Does a broadband filter help against tungsten and mercury lights?
>Does a broadband filter improve galaxy or star cluster views in light 
>polluted (tungsten and mercury. Few sodium) skies? Does it help to find 
>faint objects, say M33, under light polluted skies.
>
>Assume that, in a cluster, most of the stars have the same color. Does a 
>color filter help to block some of the light pollution without giving much 
>harm to the brightness of the cluster?
>
>Can I improve the contrast between a red nebula and the sky by using a red 
>filter? Maybe it may work like a very broad band nebula filter.
>
>I know that there are many filters with narrow bandwidth but I am looking 
>for a general solution (if exists). I mean I am looking for a solution that 
>also improves the views of galaxies or star clusters.
>
>Best wishes, clear skies
>Erhan A. Ozturk
>
>
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